#include <bits/stdc++.h>
using namespace std;
const int N=200005;
int t[N*4], n, Q, ID[N*4];
void build(int l, int r, int id) {
if(l==r) {
ID[l] = id;
t[id] = 1e9 + 1;
return;
}
int mid=(r+l)>>1;
build(l, mid, id*2);
build(mid+1, r, id*2+1);
}
void update(int u, int val) {
u=ID[u];
t[u]=val;
while(u/2!=0) {
int id=u/2;
t[id]=min(t[u], t[u^1]);
u = id;
}
}
int get(int l, int r, int id, int u, int v) {
if(v<l || r<u) return int(1e9+1);
if(u<=l && r<=v) return t[id];
int mid=(r+l)>>1;
return min(get(l, mid, id*2, u, v), get(mid+1, r, id*2+1, u, v));
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
if(fopen(".inp", "r")) freopen(".inp", "r", stdin);
cin >> n >> Q;
build(1, n, 1);
for(int i=1 ; i<=Q ; ++i) {
int c, d; char x;
cin >> x >> c >> d;
if(x=='M') {
update(d, c);
} else {
int l=d-1, r=n+1;
while(r-l>1) {
int mid=r+l >> 1;
if(get(1, n, 1, d, mid) <= c) r=mid;
else l=mid;
}
if(r==n+1) r=-1;
cout << r << '\n';
}
}
return 0;
}
